摘要
实验应用全细胞式膜片钳技术,在豚鼠球囊Ⅱ型毛细胞侧膜上研究了却(K^+)通道电流.结果表明:(1)阻断内向电流后,当钳制电位为-l00mV,以10mV的步距阶跃,阶跃从-70～+20mV,随着膜电位的去极化,可记录到一系列快速、瞬时的A型K^+通道电流,四氨基吡啶(4-Ap)对其有特异性阻断作用,激活电压为(-56.43±4.9)mV;(2)除A型K^+流外,当钳制电位为-70mV,以10mV的步距阶跃去极化-50^+40mV,可产生一系列无衰减的延迟整流性K^+流,TEA(四乙基氯化氨)能使该电流幅度下降(53.3±6.0)%.
In this experiment whole cell patch-clamp technique was used to investigate potassium current on guinea-pig saccular type Ⅱ hair cell membrane. The results showed: (1) After the inward currents were blocked,a series of rapid and instant currents of A-type potasi-um channel could be recorded when the holding potential was - 100 mV, the depolarized potentials from - 70 mV to + 20 mV in 10 mV increments. They could be blocked, especially by 4-Ap.The activated potential was (56.43 ±4.9) mV. (2) Besides A-type potassium current, when the holding potential was - 70 mV, the depolarized potentials from - 50 mV to + 40 mV in 10 mV increments, depolarization could produce a series of delayed rectifier potassium currents without any deactivation.TEA could decrease it by (53.3±6.0) % .
关键词
球囊
毛细胞
外向电流
saccule
hair cell
outward current
